Dashpot-controlled switch



May 11, 1926. 1,584,063 G. o. wlLMg y DASHPOT CONTROLLED SWITCH Original Filed Feb. 2 0. 1920 Gustav E Mlm-ns Patented May 1 1, 19,26.

UNITED STATES l1,584,063 PATENT OFFICE.

GUSTAV O. WILMS, OF MILWAUKEE, WISCONSIN, ASSIGNOR TO THE RELIANCE COM- PANY, OF MILWAUKEE, WISCONSIN, A CORPORATION OF WISCONSIN.

DAsHroT-coN'rnoLLED SWITCH.

original application inea February 2o, 1920, serial 110.366,098; Divided andthis application a1ea` February 26, 1923.

This invention relates to certain new and useful improvements in dash-pot controlled mechanism and is more particularly directed to the provision of means for regulating or controlling the time factor in they operation of the switch forming part of the mechanism. g A This application is a division of my copending one for dash-pot controlled switch filed February 20, 1920, Serial No. 360,098.

It isan important object of this invention to provide a switch, adapted to be opened upon adverse conditions in the circuit in which the same is included, employing a delay device to prevent opening of the circuit upon a momentary or temporary over-load and having means for readily adjusting the time factor in the operation of the switch.;:f-

Another object of this invention resides, in the provision of means permitting the 'ready adjustment of the time factor of the switch and having suitable designations thereon in which the time factor may be set at any definite point.

Another object of this invention resides in the provision of an improved adjustable connection between the delay device and the armature core which is actuated to overcome the delay device upon the load in the circuit increasing beyond a predetermined degree.

It is another object of this invention to vsimplify and otherwise improve the structure and the convenience with'which said devices may be adjusted for the various conditions of use] under which they would be desired to operate.

A further im ortant object resides in the provision of a ash-pot structure having its parts so arranged as to procurera des1red prolonged retarding action, with an exceedmgly short stroke of the plston member, whereby a desired compactness of structure is procured, and whereby, with respect to the switch operating solenoid, a maximum adjustment of the armature core therein may be permitted, so as to provide for desired operation of the switch mechanism under a wide range of' current conditions.

A still further object resides in the provision of an arrangement whereby the dashpot structure may be most readily connected with or disconnected from its support, to permitadjustment or inspection, and where- Serial No. 621,353.

by, in the present structure, the armature plunger member may be most readily adjusted to vary its effective length and vheld in such adjustment Awithout the use of set `screws or other members requiring independent -manipulationto permit the adjustment. I With the above and other objects in view which will' appear as the description proceeds, my invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described and more particularly defined by the ap'- pended clalms, it being understoodthat such changes in the precise embodiment. of the hereindisclosed invention may be made as come within the scope of the claims.

In the accompanying drawings, I have il- .lustrated one complete example of the physical embodiment of my invention' constructed according tothe best mode I have so far devised for the practical application of the principles thereof, and vin which: 4 Figure 1 is a side elevational view of a magnetically operated switch mechanism embodying my invention;

Figure 2 is a vertical, longitudinal, sectional view therethrough on a plane indicated by the line 2-2 of Figure 3;

Figure 3 is a mechanism; l Figure is a detail view of the adjustable connection between the armature core and the screw stem, said view being partly in section and partly in elevationand taken through Figure 2 on the plane of line 4 4; an

Figure 5 is a perspective view 'of the piston, somewhat enlarged, showing thereon the ports and the valves therefor.

plan 'view of the switch Referring now more particularly to the drawings, in the present embodiment of my invention, the various parts are carried` by a frame formed of a metallic strap 10, bent in substantially rectangular shape and provided with attaching bolt holes in the ends of the frame. A solenoid coil 11 has its conventionally shown convolutions disposed between the sides of the frame and wound upon a core sleeve 12, which has one end projected through one side of the frame to provide an annular holding shoulder, the usual end plates 13 of the coil being engaged against the inner sides of the frame.

A bushing member'lil is fitted Within the other end oit the core sleeve and extends through the other side of the frame. A tappet pin is slidably mounted in the bushing andextends through an insulating block 16 disposed on the adjacent side pf the frame, said side of the trame being disposed uppermostin the present embodiment of my invention, r

The stationary contact member of ay switch structure mounted on block 16, comprises a plate 17, secured on one end of the insulating block by a binding post 18, the Contact portionof the plate being inclined obliquely outward. The movable contact member comprises, in the present instance, a length of wire 19, doubled upon itself and havingitsend portions oppositely coiled on a bolt 20, carried by upstanding ears 21 on the remote end portion of the insulating block.

possesses considerable resilience, whereby itsA The ends of the wire are directed inwardly and engage block 16 to prevent rotation .of the 'coil portions on the bolt, and said wire bent portion, constituting the free end of the movable contact member, is resiliently urged toward the stationary contact plate 17, the wire lengthd being twisted adjacent their central bend, whereby to hold a contact button 22 for engagement with the plate. The intermediate portions of the wire lengths are oppositely bowed to fit the grooved head portion 15 ofthe tappet pin 15,'whereby outward movement of the tappet pin, upon engagement by an armature core within the solenoid, will open the switch.

`This armature core of the solenoid, which will be later described in detail, comprises 4the piston stem-0f a dash-pot arrangement,

including a cylinder '23, having an integral bottom closure and provided with a top closure plate 24, having its peripheral portion pressed downwardly and then upwardly at its extremity, to define a `flange trictionally engaging in the upper end ol the cylinder 23. The closure plate is provided I with a central plunger aperture and has its portions surroundin said aperture depressed to term a'shoulder adapted to engage about the shoulder oi' the. trame, 'formed in the present instance, bythe projected end of the core sleeve 12, whereby to properly center the dash-pot cylinder in its assembled position,

rl`he dash-pot is detachably held against the frame by a Single length of spring wire,

vbent in substantially lll-shape to provide a yoke 25, and having its ends bent inwardly to form pintles engaged in recesses 26 in the central edge portions oi" the lower side of the frame. The legs of the yoke are sinuously bent to permit resilient extension thereof, and the bight portion ot the yoke is engageable in central recesses termed vin a pair of ribs 27 on the bottom oie the dashpot cylinder, said ribs being curved to provide slide meines surfaces for the bight of the yoke, and the central portion of the bight is outwardly bent between its rib engaging portions to form a linger piece 28. The yoke will more from the recessed portions of the ribs upon lateral pressure on linger piece 28, and thus the dash-pot cylinder may be most readily assembled or disassembled with respect to the frame by swinging the retaining yoke ou the pivots atl'orded by its pintle ends.

The bottom of the dash-pot is provided with a plurality of upstanding annular wall sections 29, concentric with the wall olf the dash-pot cylinder, and a piston 30 is loosely fitted within the dash-pot cylinder and carries a plurality of depending wall sections 3l, adapted yto loosely lit between the wall sections 29 and the ymain wall of the cylinder, said piston also carrying a depending central projection 32 engageable in the space bounded by the inner; `cylinder wall section 29. A pair of upper dash-pot chambers are thus defined at the tops of walls 29, which ,increase in volume as the piston is drawn bottom of the central projection 32 oil' the piston. 4

lintake Ior timing ports 33 extend through the piston and communicate with the upper dash-pot chambers, while relatively large outlet ports 34, having cheek valve balls 35 therein, are also extended through the piston and communicate with these chambers, the balls being held in place by a plate 3G secured on the'piston and having its ends projecting over portions of the outlet ports. A common control for the intake ports 33 is afforded by a timing valve plate 37, pivoted on the piston betweenthe ports and having edge portions projecting over the ports, said plate being movable against considerable friction resistance to thus adjust the flow capacity of the inlet ports and procure a corresponding adjustment of the time interval ot operation of the dash-pot upon a. given pull.

By reason oie the loose tit between the various wall sections, any suitablefluid which is provided for the dash-pot will pass 'through the ports 33 in lifting movement the inertia and increase-d friction oit' the fluid in following; such tortuous paths.

The interior of the dash-pot cylinder-is;-

provided with longitudinal channels 38, exitending from its top to a point adjacent the tops of the wall sections 31. Thus,as the piston-is raised during the desired time 1nterval of thedetent action, the limit of such interval will be determined by movement ot the piston wall portions, past the tops of the cylinder wallA portions, atwhich time free flow of fluid under the piston will be permitted through the channels 38,- thus permitting a quick upper movement (of the piston at the limit of its desired detent action, to procure the required operation of the piston stem. The piston is heldagainst rotation .in the cylinder by lugs 39, projecting from its peripheral portion into certain of the channels 38, the width of said lugs bc-` ing, however, less than thewidth ot the channels, so as not to interfere with free How of fluid through the channels in the release action. Y

ln the present structure, the stem or plunger of the piston comprises a pair of 'adjustably connected parts, the upper part l constituting an armature core engageable in the sleeve 12, in the form of a cylindrical member 4 0, having a bore in its lowerfend portion, `threaded to receive a screw 41, which constitutes the lower sectionotthe stem, the head of the screw being preferably cast in the piston body. The upper portion ofthe armature core 40 is chamberedto receive a retaining wire member 42, bent in inverted U shape with the lower end portion of one of the legs further bent in the form of an eye 43, embracing the screw 41, and the other leg extended within a longitudinal slot 44, formed in the sidek of the core member with its lower end bowed inwardly and constituting a pawl engageable with the screw and adapted to yieldably set in a longitudinal groove-45 cut in the screw, whereby the core member is yieldably held against movement on the screw, `the sides of the slot 44 bracing the wire `pawl portion against distortion. The upperl end of the core member is closed by a cap plate 46, set withinl its chamber and retaining the Lspring in place.

The extent to which the armature core projects into the coil in 'the initial or depressed position of the dash-pot plunger obviously determines the act-ionot the dashpot mechanism with respect to the amount of current passing through the coil, and the core member may thus be set by adjustment on the screw for the desired operation of dash-pot mechanism at different rates of current. This adjustment can be conveniently effected by simply swinging the holding yoke 25 owlthe dash pot cylinder to one side, to pcrmit'ren'ioval of the cylinder, and then grasping and turning the core member, the piston being held against the turning movement by its lugs 39, as described. This ad'- justment may be thus etected in a most current conditions, is adjusted as described,

by means ot the valve plate 37, access to said plate being afforded by forcing the top plate 24 from the cylinder, which may be readily one by reason of its friction'al fit.

I have thus provided an exceedingly compact and eliicient'dash-pot control mechal nism, which is of simple and durable construction and -which may be most conveniently adjusted for the various conditions of use required. i

The device constituting the present embodiment of my invention is commonly termed ari overload relaypswitch', and in use thereof, the solenoid coil l1 would be connected in series with a motor or the-like, andv the contact members of the device would be connected in series with thecoil ycircuit of the main controlling switch.A The dash-pot mechanism affords an inverse time limit'onl the operation of theswitch, causing the actuating armature core 40 to move slowly von a' mild over-load and permitting its very i rapid movement on a serious overload. This time limit feature makes it possible to set the switch so as to protectthe motor against bona fide, dangerous overload and yet pre-. vent operation of the switch and consequent stopping` ofthe motor incidental to temporary, trivial overload conditions, the retarding action'of the switch also serving to prevent its operation during the relatively heavy current period necessary in starting a motor. l

What I claim as my invention is:

l'. A device ofy the character described, comprising a solenoid coil, a head member, a screw stem section yextending' from the head member, an armature core section threaded onthe screw section and provided with a `slot in its side, and a spring pawl member in said slot and engaging the screw section.

2. A device of the character described,

comprising a screw stem section, a movablek member threaded on the screw section and having a chamber in its outer end communieating with aslot in the side thereof, and a length of spring insaid chamber bent with one end portion extended in the slot and engaging the screw section.

3. A device of the character described, comprising a screw stem section,a movable member threaded on the-,screw section and having a chamber inits outer end communieating with a slot in the side thereof, and a a chamber length of spring in said chamber' bent in substantiallyl U- shape with one en'd portion in the slot and engaging the screw section.

4. A device of the character described, comprising al movable member having in one end with a threaded bore in the other end comn'iunicating there.- With and a slot in itsside communicating with the bore, a screw stem adapted to be threaded in said bore, and a spring in said chamber with one end portion curved and extended in the slot and its other end portion formed into an eye througbrwhich the screw section passes.

5. A device of `the character described,-

comprising a movable membei having a chamber in one end with a threaded bore in the other end communicating therewith and a slot in lits side communicatingy with the bore and the chamber, a'screw stem adapted to be threaded in said bore, a spring in said chamber bent in substantially itl-shape with comprising a solenoid coil, ahead member,

a stem extending from the head member, an armature core movable upon the stem, and resilient means carried bythe core and enageable 4with the stem for locking the two in a predetermined adjusted position.

8. .In-'a control mechanism, the combination of an actuating solenoid-coil, a dash-pot detachably connected at one end of the coil, a piston movable within` the dash-pot, a threaded stem carried by the piston, a solenoid plunger receiving therein the threaded portion'o'f the stem, and resilient means carried by the lunger and engageable with the stem or ho ding the; lunger in a predetermined position upon `t e stem.

9. In a control mechanism, the combination or' an actuating solenoid coil, a dash-pot detachably connected at one end of the coil,

neeaoee 'itsrmovemen a solenoid plunger comprising an inner section carried by the piston, and an outer section threadedly connected with the inner section and extending into the solenoid coil and lugs on the piston engaging Ain the channels to prevent rotation of the piston upon adjusting rotation of the outer plunger section.

11. A device of the character described,

comprising a solenoid coil, a head member,

i a stem extending from the head member, an

armature core movable Vupon the stem, and means carried by the core and movable in a planeet right angles to the stem for engagement therewith for holding the core vin a predetermined position upon the stem.l

l2. A switch mechanism of the class described, comprising a solenoid coil, a stationary contact member at one side of the coil, a movable'contact 'member 'formed of a single length of wire, doubled upon itself and having its end portions secured at the opposite side of the coil, said member being resiliently urged toward 'the stationary Contact member, a tappet pin slidable co axially with the coil, the 'intermediate por tions.. of the' wire being oppositely bowed to embrace and hold the' pin and a solenoid core slidable in the coil and engageable with said pin. to open the switch;

13. A device of the character described, comprising a solenoid coil, a head member, a stem extending `from the head member, a hollow armature core movable-upon the stem and having 'therein a slot, and resilient means positioned within the, core and movable through the slot 'for engagement vwith the stem for holding saidcore in a predetermined position upon the stem.

ln testimony whereof l aiix my signature.

GUSTAV O. WILMS. 

